Aftermath of Boston Bombings

BOSTON, MA - APRIL 16: After the barricades were moved up along Boylston street to the corner with Berkeley people walk along holding flags and memorials following yesterday's bomb attack on the Boston Marathon April 16, 2013 in Boston, Massachusetts. Security is tight in the City of Boston following yesterday's two bomb explosions at the finish of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A man takes a picture on Boylston and Berkeley street following yesterday's bomb attack on the Boston Marathon April 16, 2013 in Boston, Massachusetts. Security is tight in the City of Boston following yesterday's two bomb explosions at the finish of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: After the barricades were moved up along Boylston street to the corner with Berkeley people walk along holding flags and memorials following yesterday's bomb attack on the Boston Marathon April 16, 2013 in Boston, Massachusetts. Security is tight in the City of Boston following yesterday's two bomb explosions at the finish of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: After the barricades were moved up along Boylston street to the corner with Berkeley people walk along holding flags and memorials following yesterday's bomb attack on the Boston Marathon April 16, 2013 in Boston, Massachusetts. Security is tight in the City of Boston following yesterday's two bomb explosions at the finish of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A Boston Police officer lifts the tape for a family to leave flowers in front of the home of the Richard family whose eight-year-old son, Martin, was killed by an explosion near the finish line of the Boston Marathon, on April 16, 2013 in Boston, Massachusetts. The twin bombings resulted in the deaths of three people and hospitalized at least 128. The bombings at the 116-year-old Boston race resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Jared Wickerham/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Boston State Police stand guard in the baggage claim area of Logan International Airport on April 16, 2013 in Boston, Massachusetts. Security is tight in the Boston following yesterday's two bomb explosions at the finish of the Boston Marathon, which killed three people and injured at least 176 others. (Photo by Jared Wickerham/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Boston Police officers stand guard blocks away from the scene of yesterday's bombing attack at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Members of the Federal Bureau of Investigation (FBI) stand near near the scene of yesterday's bombing attack at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Boston Police officers stand guard blocks away from the scene of yesterday's bombing attack at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: National Guard soldiers speak with pedestrians as they guard a roadblock near the scene of yesterday's bombing attack at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Flowers are left at a security gate near the scene of yesterday's bombing attack at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Nicholas Yanni of Boston, MA, describes the blast and his injuries during a press conference at Tufts Medical Center after being injured at yesterday's bomb attack on the Boston Marathon April 16, 2013 in Boston, Massachusetts. Yanni who was a bystander and his wife Lee Ann was also hurt in the blast.Two bombs exploded near the finish of the marathon, killing three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: FBI Special Agent in Charge Richard DesLauriers (C) speaks at a press conference April 16, 2013 at the Westin Copley in Boston, Massachusetts. Security is tight in the City of Boston following yesterday's two bomb explosions at the finish of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A heavily armed Boston police officer stands blocks away from the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: National Guard soldiers guard a roadblock near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A National Guard soldier checks identification near a roadblock near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A discarded runners bib is viewed near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A runner stands at a security gate near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Unused thermal blankets for marathon participants are piled near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: The unfinished meals of fleeing customers are left on tables at an outdoor restaurant near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Claire Schaeffer Dufy walks with a sign she made to support her runner husband, Scott, near the scene of a twin bombing at the Boston Marathon on April 16, 2013 in Boston, Massachusetts. The twin bombings, which occurred near the marathon finish line, resulted in the deaths of three people while hospitalizing at least 128. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON - APRIL 16: A sign on a door makes notice of being closed at Trident Booksellers Cafe on Newbury Street shows closed on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON - APRIL 16: Newspapers are on sale at a stand on Newbury Street on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON - APRIL 16: A SWAT team vehicle stands guard on Dalton Street near Boylston Street on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A police officer stands guard at the corner of Boylston and Arlington Streets with the marathon finish line bridge in the distance on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Swat team members and special police units assemble in the Boston Common on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Police units assemble along the Boston Public Garden on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Photo by Darren McCollester/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: A Boston police officer stands near the scene of a twin bombing at the Boston Marathon, on April 16, 2013 in Boston, Massachusetts. Three people are confirmed dead and at least 141 injured after the explosions went off near the finish line of the marathon yesterday. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON, MA - APRIL 16: Unclaimed finish line bags are viewed near the scene of a twin bombing at the Boston Marathon, on April 16, 2013 in Boston, Massachusetts. Three people are confirmed dead and at least 141 injured after the explosions went off near the finish line of the marathon yesterday. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

Photo: Spencer Platt/Getty Images

BOSTON, MA - APRIL 16: Debris and litter cover an empty street near the scene of a twin bombing at the Boston Marathon, on April 16, 2013 in Boston, Massachusetts. Three people are confirmed dead and at least 141 injured after the explosions went off near the finish line of the marathon yesterday. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Photo by Spencer Platt/Getty Images)

Boston Deals With Aftermath Of Marathon Explosions

BOSTON - APRIL 16: Investigators in white jumpsuits work the crime scene on Boylston Street following yesterday's bomb attack at the Boston Marathon April 16, 2013 in Boston, Massachusetts. Security is tight in the City of Boston following yesterday's two bomb explosions near the finish line of the Boston Marathon, that killed three people and wounding hundreds more. (Photo by Darren McCollester/Getty Images)